Fig. 7: Inhibition of DPP4 alleviates intrauterine growth restriction caused by pulmonary coronavirus infection modeled by intranasal MHV inoculation.

a Fpkm values of Dpp4 expression in lungs infected with either DMEM (n = 3) or MHV (n = 3). b Schematic diagram illustrating the timeline of MHV infection and sitagliptin treatment of pregnant mice (Created in BioRender. Ding, X. (2026) https://BioRender.com/lfokc6w). c Changes in body weight of pregnant mice infected with either DMEM (n = 4) or MHV alone (n = 3), or treated with sitagliptin (n = 3). d–k Maternal deciduas were collected at embryonic day 12.5 (E12.5) for analysis. d, e Representative images of uterus, fetuses and placentas (d) and statistical analysis of the length and weight of fetuses and the diameter and weight of placentas (e) infected with either DMEM (n = 41 for length of fetuses, n = 33 for weight of fetuses, n = 32 for diameter of placentas, and n = 32 for weight of placentas) or MHV alone (n = 24 for length of fetuses, n = 23 for weight of fetuses, n = 24 for diameter of placentas, and n = 22 for weight of placentas), or treated with sitagliptin (n = 24 for length of fetuses, n = 25 for weight of fetuses, n = 20 for diameter of placentas, and n = 19 for weight of placentas). scale bar, 2 mm. f, g Representative images of H&E staining of vessels in decidua sections (f) and statistical analysis of the thickness of vessels (g) infected with either DMEM (n = 21) or MHV alone (n = 4), or treated with sitagliptin (n = 7). scale bar, 50 μm. h Representative images of immunohistochemistry staining of Cytokeratin in decidua sections infected with either DMEM or MHV alone, or treated with sitagliptin. scale bar, 50 μm. The red line indicates the boundary between the maternal and fetal sides. The red star marks the site of trophoblast invasion into the decidua. M maternal, F fetal. i Representative images of immunofluorescence staining of IL1R2 in decidua sections infected with either DMEM or MHV alone, or treated with sitagliptin. scale bar, 20 μm. j Transcriptomic analysis of differentially expressed genes in deciduas infected with either DMEM (n = 3) or MHV alone (n = 3), or treated with sitagliptin (n = 3). k Gene Ontology (GO) of Biological Process (BP) analysis of differentially expressed genes in deciduas infected with either DMEM (n = 3) or MHV alone (n = 3), or treated with sitagliptin (n = 3). Results are representative of two or three independent experiments. All bars in the graphs represent the mean ± s.e.m. Statistical comparisons were performed using a two-tailed unpaired Student’s t test (a), one-way analysis of variance (ANOVA) with Dunnett’s multiple comparisons test (c) and one-way ANOVA with Tukey’s multiple comparisons test (e, g). Statistical significance of differential gene expression (j) was determined by the Wald test (two-sided) implemented in DESeq2, with P values adjusted for multiple comparisons using the false discovery rate (FDR) method. Statistical significance of pathway enrichment (k) was determined by the hypergeometric test (one-sided), with P values adjusted for multiple comparisons using the false discovery rate (FDR) method. Source data are provided as a Source Data file.